Genuine Black & Decker N563941 trimmer guard assembly for compatible Black & Decker ST1823, ST1823B and ST182320 cordless string trimmers. This replacement guard fits around the cutting head to help protect the user from grass, debris and contact with the rotating cutting line during operation. Suitable for replacing a cracked, damaged or missing original guard and manufactured to the correct Black & Decker specifications for precise fit and reliable protection.